1. Field of the Invention
The invention concerns a microwave generator with a high spark gap between colinearly arranged electrodes.
The function of such a generator is based on the fact that a high voltage battery, for example a capacitor battery which is charged up in parallel on the basis of the principle of the Marx impulse voltage circuit and then connected in series, is discharged by way of a spark gap which is set between the electrodes, across which the high voltage of the series circuit is then applied. Such a discharge process results in a flow of current which starts steeply and oscillates severely, in the electrodes and in antenna conductors which are possibly additionally electrically conductively connected thereto, and it thus results in correspondingly wide-band irradiation of a microwave spectrum of high energy density, which in the environment of such a microwave generator can at least adversely affect radio communications and disturb or even destroy electronic circuits in particular at the input side.
2. Discussion of the Prior Art
That effect of intensive microwave irradiation is therefore propagated as a non-lethal weapon against hostile communication systems (see DER SPIEGEL, issue July 1997, pages 53 ff, end of paragraph 3 in the left-hand column on page 54).
The object is attained by the essential features of the invention in that on both sides of the spark gap, the electrodes and coaxial holders thereof are accompanied at least over a part of their axial lengthwise extension by an electrical conductor which extends in spaced relationship therewith and which is electrically conductively connected to one of the electrodes.
In accordance with the present invention, two electrodes are disposed in mutually opposite axially spaced relationship to define a spark gap coaxially in the interior of a tubular housing at a radial distance relative to the inside wall. That pair of electrodes represents a capacitor in which high voltage energy is stored until the abrupt energy discharge occurs as a result of flash-over across the spark gap. For charging up that capacitor, each of the two electrodes is held insulated at an end of the housing and is electrically connected to a high voltage generator. This preferably involves a Marx impulse voltage circuit of small size, whose capacitor battery is charged up statically from a direct current source or dynamically from an electromechanical pulse generator in a parallel circuit, before it is switched over into a series relationship, the correspondingly multiplied voltage of which is applied to the pair of electrodes of the above-mentioned spark gap and results in firing thereof.
In addition, arranged in the interior of the housing radially spaced with respect to the spark electrodes and in parallel relationship therewith is at least one hollow-cylindrical conductor which preferably also extends axially, beyond the electrodes, over at least a part of the electrode holders. This conductor which serves as a tuneable resonator antenna is connected for resonance detuning over the very wide range of at least approximately one octave, at a location which is longitudinally variable to one of the two electrode holders. As a consequence of that arrangement, the conductor acts as a variably frequency-determining member which at the same time increases the length of pulses as desired as a result of transit time effects. This occurs for the current oscillations which are triggered by the high voltage discharge across the spark gap with a steep current rise edge and which therefore radiate vigorously and which involve a variable frequency point of concentration. In the high radiated interference energy which is proportional to the pulse length, that permits specific and targeted adaptation of the centre region of the effective wavelengths. The wavelengths can be targeted approximately to the spatial dimensions of the conductor path geometry in the input circuit of a respective given type of computers or communication devices in order there to achieve overmodulation effects or even joulean destruction effects as a consequence of an excessive resonance increase in the microwave voltage which is coupled thereto. Accordingly this system according to the invention, as a high-energy pulse interference or jamming device which can be optimized in terms of frequency, is more effective by orders of magnitude than the conventional production of CW interference energy in the form of damped sinusoidal oscillations. On the other hand, by virtue of the wide-band nature of the interference generator according to the invention, adaptation of an interference frequency to the electromechanical dimensions of the system to be interfered with is not precisely required.